Cycle controlling device



April 2, 1946.

P. VAN SlTTERT ETAL CYCLE CONTROLLING DEVICE Filed Feb. 8, 1943 /a e l;it: i

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s s 53 4 b 50 48 55 INVENTORS PA UL N \SITTEE BY W/L IAA4 K0VACSATTORNEY Patented Apr. 2, 1946 CYCLE CONTROLLING DEVICE Paul VanSittert, Shaker Heights, and William R. Ohio, assignors to The ClevelandPneumatic Tool Company, Cleveland, Ohio, a corporation of OhioApplication February 8, 1943, Serial No. 475,094

. Kovacs, Cleveland,

3 Claims.

The present invention relates broadly to fluid actuated tools ingeneral, but more particularly to fluid actuated riveting hammers of thetype used for upsetting rivets. Still more particularly,

this invention deals with an improved cycle control or timing device forfluid actuated riveting hammers.

The primary object of the invention is to provide an improved mechanismwhich will control the cycle of operation of a riveting hammer to anextent whereby pressure will be gradually applied to accelerate thehammer for upsetting the rivet and as soon as the pressure reaches apredetermined maximum, the cycle will be automatically terminated,thereby shutting oif the pressure to the hammer.

Another object of the invention is to provide a mechanism having theabove characteristics which can be attached to, or incorporated in, thehandle of a fluidactuated riveting hammer with but slight modificationof the tool.

A further object of the invention resides in the provision of animproved cycle control or timing device for fluid actuated rivetinghammers which functions to deliver a predetermined time cycle and thenstops, thus accurately producing rivet bucktails of uniform height anddiameter.

Other objects and advantages more or less ancillary to the foregoingreside in the specific construction and aggroupment of the elementspeculiar to this structure, as will become apparent from a more completeexamination of this specification.

In the drawing which illustrates the invention:

Fig. 1 is a side elevational view of a riveting hammer embodying theinvention, the handle and attachment being in section to show details ofconstruction.

Fig. 2 is a view of a portion of the handle shown in Fig. 1 with theparts in another position.

Referring to the drawing for a more detailed description thereof, afluid actuated riveting hammer is generally designated by the referencenumeral 5 and includes a cylinder 6 having a piston (not shown)reciprocable therein and active on a rivet set I which is operativelymounted within the front end of the cylinder 6 and secured in positionby a suitable retainer 8. To the cylinder 6 is threaded, or otherwiseafdxed, a handle' 9 provided in its upper end with a verticallyextending passage ||l which leads into the cylinder 8 for admittingmotive fluid such as compressed air therein to effect reciprocation ofthe piston. The passage ID at its lower end communicates with arelatively large cylindrical bore I, and extending diagonally therefromtoward the lower end of the handle is a passage l2. Motive fluid isadmitted into the passage I0 through the threaded connection l3 fromwhich extends a gooseneck coupling The handle I0 is provided with atrigger I5 which is mounted for slidable movement within a bore I6formed in said handle adjacent its connection with the cylinder 6. As isto be understood, the trigger I5 is adapted to be depressed by theoperator of the tool for admitting fluid to the cylinder 6 for effectingreciprocation of the piston housed therein. A lever I1 is pivotallyconnected at one end by pin and slot means as indicated at i8 to thetrigger I5 and the other end thereof connected at l9 to the handle 9.The lever i1 is formed with a cam-like projection 20 which normallyengages the upper end of a slidably supported rod 2| for a purpose to behereinafter more fully described.

The lower end of the handle 9 is formed with an interiorly threadedopening 22 which com= municates with the bore H and receives one end 23of a housing 24, the other end 25 of said housing being interiorlythreaded as indicated at 26 for attachment with the end of a motivefluid supply conduit (not shown) The housing 24 is adapted to containand support the improved mechanism for automatically controlling thecycle of operation of the riveting hammer to an extent whereby pressurefluid will be gradually fed to the cylinder t for accelerating the rivetset i and the pressure gradually built up until a predetermined maximumhas been reached at which time the cycle will be automaticallyterminated. The mechanism for accomplishing this function includes atubular shaped plunger 27 slidable within a bore 28 and having one end29 projecting into the bore The rod 2| is integral with, and extendsfrom, the end 29 through a bushing 30. Depressing the trigger l5 willeffect contact of the lever I! with the end of the rod 2| and will urgesaid rod and its plunger 21 downwardly within the bore 28. A compressionspring 3| surrounds the plunger 21 within the bore and normallymaintains said plunger in the inoperative position shown in Fig. 1 ofthe drawing.

The lower end of the plunger 21 is of reduced diameter as indicated at32 and said reduced end is formed with a channel 33 for slidablysupporting a stem 34, said stem being formed with a slot 35 forreceiving a pin 36 which projects from the reduced end 32. Thisconstruction permits the stem 34 to move with the plunger 21 in a mannerto be hereinafter more fully described. The stem 34 carries apiston-like member 91 and said member is normally used downwardlybymeans of the compression spring 39.

The threaded opening 26 communicates with a relatively large recess 39,the outlet of which is controlled by means of a valve 40 andspring 4|,said spring acting to retain the valve on its seat. The valve 49 isoperatively connected with the member 31 by means of a pair of links 42and 43. Link 42 is pivotally connected at 44 to the member 31, while thelink 43 is pivotally' connected to the valve 40 as indicated at 45. Theadjoining ends. of the links 42 and 43 are pivotally connected asindicated at 46 and a pin 41 projects from the member 31 for guiding andmaintaining said links in a vertical position upon downward movement ofthe plunger 21.

Projecting from the bore 28 is a horizontally extending passage 48 whichcommunicates with a relatively large bore 49 through the recess 54, saidbore as being arranged in parallel relation with the principal portionof the passage 49. Slidably mounted within the bore 49 there is a valve50 backed by a compression spring and said valve is formed with atapered or conical portion 52 which is integral with a piston 53 of adiameter substantially equal to the diameter of the bore 49. In theinoperative position shown in Fig. i of the drawing, the valve 59 actsto completely close the recess 54. The bore 49, intermediate its ends,is slightly enlarged as indicated at 55 from which radiates an outlet 56leading into a horizontal passage 51. At a point diametrically oppositefrom the outlet 56, the assage 51 is provided with a coupling 58 whichforms the other end of the gooseneck connection i4. From theconstruction just described it will be understood that with the valve inopen position, air under pressure is free to flow through the passage 48into the bore 49 through the outlet 56 and into the gooseneck couplingI4. The inner end of the bore 49 communicates with a restricted passage69 which passage extends from, and connnunicates with, the passage 48.

This permits a portion of the fluid that would normally flow through thepassage 48, to flow through the passage 59 for action upon the piston 53to move said piston and its connected valve toward the Fig. 2 positionagainst the tension of the spring 5| thereby uncovering the recess 54 toallow the fluid to enter the bore and be pletely uncovered, at whichtime maximum pres-- sure will be applied to the hammer.

The passage 51 has one end closed by means of a screw plug 69 and saidplug slidably supports a rod 6| to which is attached a cylinder 62. Ahead 63 is formed on the projecting end of the rod 6| and interposedbetween said cap and the plug 60 is a compression spring 64 for normallyurging the rod outwardly or away from the housing 24. The tension of thespring 64 can be adjusted through the nut 69. The cylinder 62 isslidable within the passage 51 and its outward movement is limited bymeans of a stop 65. The passage 61 communicates with the atmospherethrough 'a vent opening 66 and a similar vent opening 61 is provided forconnecting the bore 49 with the atmosphere. The rod 6| is slidable in apassage 69 which is a continuation oi-the passage 61 and projects intothe bore 26 at a point in line with the pivotal connection 01' the links42 and 43.

In the operation of the device,,the parts are normally all in therelation and position shown in Fig. l of the drawing. After positioningthe rivet set I adjacent the rivet to be upset, the operator depressesthe trigger II to urge the rod 2| and plunger 21 downwardly through themedium of the lever l'l. Downward movement of the plunger 21 causes thestem 34 and member 37 to be moved downwardly and carried after apredetermined interval of time.

therewith are the links 42 and 43 and the valve 49. This downwardmovement unseats the valve 40 and motive fluid under pressure from thesupply line enters the passages 48 and 59 simultaneously. The fluidentering the passage 59 will act upon the piston 63 to urge the sameoutwardly against the tension of the spring 6|.

thereby allowing the-fluid from the passage 48 to be admitted throughtherecess 54 into the bore 49 and enlarged opening 66 of said bore. Fromthe opening 55, the fluid flows through the outlet 56 into the passage61 and then passes through the coupling 69 and through the gooseneckcoupling i4 for discharge into the conduit i2 and passage iii and fromthe latter flows into the hammer cylinder. As before indicated, thepressure is gradually applied to the hammer due to the taperedconstruction of the valve 50. A certain percentage of fluid flowing intothe passage 5l irom the outlet 66 will be discharged toward the cylinder62 to move the same and its rod 6| until said rod is brought intocontact with the links 42 and 43 which contact will collapse the links,as illustrated in Fig. 2, thereby pulling the valve upwardly against itsseat and shutting oil further flow of fluid from the source of supply.Contact of the rod 6| with the links thus terminates the cycle and theoperator releases his pressure on the trigger to permit the parts toreturn to their normal positions under the action of their respectivesprings.

From the above description when taken in connection with theaccompanying drawing, it will be readily apparent that the improvedmechanism permits the gradual increase of power on the piston which willbe automatically terminated The period of the-cycle is under the controlof the adjustable plug 69 and spring 94. As is understood, the-plug 69is adjusted for increasing or decreasing the tension or the spring 64and since the cylinder 62 and rod 6| operate against the tension of saidspring, speed of movement thereof is controlled by the amount of tensionplaced on said spring. A needle valve 63 is positioned in the passage 69for controlling the action of the piston 63. Use of the needle valve 69to restrict the passage 69 will, of course, delay the action of thepiston 53 thereby permitting air under pressure to be more gradually fedto the hammer cylinder and conversely by opening the valve 69 so that anunrestricted passage is provided, the piston will be acted upon at agreater rate of speed and thereby allow the pressure of air to be morerapidly built up in the hammer cylinder before it is terminated by theaction of the rod 6| contacting the links 42 and 43 to close the valve49,. The entire operation is automatic since after depressing thetrigger, the timer delivers a predetermined time cycle and then stops,thus accurately producing rivet bucktails of uniform height anddiameter. Use or this improved mechanism insures uniform riveting whenseveral rivets are driven in sequence and avoids the usual re-hitting orover-hitting which frequently requires drilling out and replacement ofrivets, In addition, since the riveting cycle is pre-set and ceasesautomatically when the rivet has been upset, little or no damage to thesheet will be experienced, thus saving not only in rejects but also inmaterial.

Although the foregoing description is necessarily of a detailedcharacter, in order to completely set forth the invention, it is to beunderstood that the specific terminology is not intended to berestrictive or confining and it is to be further understood that variousrearrangements of parts and modifications of structural detail may beresorted to without departing from the scope or spirit of the inventionas herein claimed.

.We claim:

1. In a mechanism for controlling the operation of a riveting tool orthe like, a housing having therein an inlet adapted to be connected witha source of fluid pressure and an outlet, a passage within the housingconnecting said inlet and outlet including a valve chamber, a valve insaid inlet, manually operable means for opening said inlet valve, ameasuring valve in said valve chamber responsive to the pressure ofincoming fluid for gradually opening and thereby radually building upfluid pressure in said outlet, and means responsive to the finalpressure of fluid in said outlet for causing the closing of said inletvalve.

2. In a mechanism for controlling the oper tion of a riveting tool orthe like, a housing having therein an inlet adapted to. be connectedwith a source of fluid pressure and an outlet, a passage therefrom, anda piston operable in said cylinder and engageable with said linkage toflex the same and cause closing of said inlet valve after apredetermined time interval, for building up the pressure to apredetermined maximum.

3. In a mechanism for controlling the operation of a riveting tool orthe like, a housing having therein an inlet adapted to be connected witha source of fluid pressure and an outlet, a passage within the housingconnecting said inlet and outlet including a valve chamber, a valve insaid inlet, a bore in said housing, manually operable means in said borefor opening the inlet valve including a linkage for transmitting motionto the latter, a fluid actuated valve in said valve chamber operable tocause a gradual building up of fluid pressure in said outlet, means forrestrictin the flow of actuating fluid to said fluid actuated valve, acylinder in said housing connected with said valve chamber to receivepressure fluid therefrom, and a piston operable in said cylinder andengageable'with said linkage to flex the same and cause closing or saidinlet valve after a predetermined time interval, for building up thepressure to a predetermined maximum.

PAUL VAN SI'II'ERT. WILLIAM R. KOVACS.

